# US02-03 — Execute Jobs with Leases, Locks, and Recovery

Epic: [E02](../E02-unified-workflow-shell.md)

As an operator, I want workers to claim, cancel, and recover jobs safely so crashes or
duplicate workers cannot corrupt state.

## Acceptance criteria

- Workers use leases, heartbeats, fencing tokens, bounded queues, and typed lanes.
- Cancellation is cooperative and leaves resumable or terminal item states.
- Lock ordering prevents conflicting analysis, EXIF, rename, upload, and archive work.
- A recovered job rejects late commits from its former worker.

## Automated tests

- Process tests kill workers, expire leases, recover jobs, and attempt stale commits.
- Randomized concurrency tests assert no deadlocks, duplicate completion, or lost events.

## Dependencies

- US02-02